1. Field of the Invention
The present invention relates to a pool guard alarm apparatus, and more particularly to an alarm apparatus that is effective in preventing unauthorized persons from entering an area around a pool and sounds an alarm when a person enters the protected pool area.
2. Description of the Prior Art
It is an important security management to prevent a stranger or young child from entering an area around an outdoor pool. Sometimes, accidents occur. It is especially dangerous for infants and younger children to enter the pool area when there is no lifeguard or other supervision present. Most outdoor pools have a pool gate for entrance to the pool area. In practice, the gate is often opened by unauthorized persons. Therefore, a simple and effective device is provided at the door or gate that will sound an alarm as soon as the gate is opened.
A conventional pool guard alarm, as disclosed in U.S. Pat. No. 5,473,310, comprises a sensor composed of a magnet and a magnetic switch to detect the entrance of an area around a pool, a high output alarm unit having a delay timer activated via a battery, a housing to accommodate the alarm and the battery, and a reset button located on the housing. The housing and the sensor are located at the entrance to the pool area. The reset button must be pressed within a short time after opening and passage through, or an alarm is sounded whether or not the gate was closed. This design prevents unauthorized persons from entering the pool area and sounds the alarm as soon as the unauthorized persons enter the protected area. There are several disadvantages in the design of the aforesaid patent:    1. An iron gate decreases the magnetism of the trigger, as well as interfering with the magnetic switch, which causes the sensor to malfunction and cause a false alarm.    2. The sensor uses the magnet to attract and activate the magnetic switch. The magnetic switch can easily be out of the scope of the magnetism of the magnet due to wind or other external forces, which may produce an inadvertent contact which will influence the precision of the alarm.    3. This alarm uses a single reset button to bypass the alarm mode. This limits the effectiveness of the protection of the area since anyone can simply push the button to enter without sounding the alarm.
Accordingly, the inventor of the present invention has devoted himself based on his many years of practical experiences to the development of a pool guard alarm apparatus to overcome the above shortcomings.